fix: allow empty URL when saving asset profile (#6811)

`@IsOptional()` from class-validator only skips validation for `undefined`
or `null` - not for empty string `""`. The asset profile dialog submits
`url: ""` when the optional URL field is left blank, so `@IsUrl()` runs
and the form fails with "url must be a URL address" despite URL being
documented as optional.

Fix: add a `@Transform` that coerces empty/whitespace-only strings to
`undefined`, letting `@IsOptional()` short-circuit the validation chain.
Same pattern as the `comment` field in `update-account.dto.ts`.

Applied to both `UpdateAssetProfileDto` (the form path in the bug repro)
and `CreateAssetProfileDto` (same flaw, same flow). Platform DTOs are
left alone since their `url` field is required (not optional).

Closes #6811.

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Upgraded `stripe` from version `20.4.1` to `21.0.1`
 
+### Fixed
+
+- Fixed the asset profile validation to allow saving with an empty URL field
+
 ## 3.1.0 - 2026-04-29
 
 ### Added

libs/common/src/lib/dtos/create-asset-profile.dto.ts

@@ -1,6 +1,7 @@
 import { IsCurrencyCode } from '@ghostfolio/common/validators/is-currency-code';
 
 import { AssetClass, AssetSubClass, DataSource, Prisma } from '@prisma/client';
+import { Transform, TransformFnParams } from 'class-transformer';
 import {
   IsArray,
   IsBoolean,
@@ -9,6 +10,7 @@ import {
   IsString,
   IsUrl
 } from 'class-validator';
+import { isString } from 'lodash';
 
 export class CreateAssetProfileDto {
   @IsEnum(AssetClass, { each: true })
@@ -77,5 +79,8 @@ export class CreateAssetProfileDto {
     protocols: ['https'],
     require_protocol: true
   })
+  @Transform(({ value }: TransformFnParams) =>
+    isString(value) && value.trim() === '' ? undefined : value
+  )
   url?: string;
 }

libs/common/src/lib/dtos/update-asset-profile.dto.ts

@@ -1,6 +1,7 @@
 import { IsCurrencyCode } from '@ghostfolio/common/validators/is-currency-code';
 
 import { AssetClass, AssetSubClass, DataSource, Prisma } from '@prisma/client';
+import { Transform, TransformFnParams } from 'class-transformer';
 import {
   IsArray,
   IsBoolean,
@@ -10,6 +11,7 @@ import {
   IsString,
   IsUrl
 } from 'class-validator';
+import { isString } from 'lodash';
 
 export class UpdateAssetProfileDto {
   @IsEnum(AssetClass, { each: true })
@@ -67,5 +69,8 @@ export class UpdateAssetProfileDto {
     protocols: ['https'],
     require_protocol: true
   })
+  @Transform(({ value }: TransformFnParams) =>
+    isString(value) && value.trim() === '' ? undefined : value
+  )
   url?: string;
 }